This chapter shall be known and may be cited as the "Upper Hanover
Township Stormwater Management Ordinance."
The Board of Supervisors hereby finds that:
A.
Inadequate management of accelerated runoff of stormwater resulting
from development throughout a watershed increases flood flows and
velocities, contributes to erosion and sedimentation, changes the
natural hydrologic patterns, destroys aquatic habitat, elevates aquatic
pollutant concentrations and loadings, overtaxes the carrying capacity
of streams and storm sewers, greatly increases the cost of public
facilities to carry and control stormwater, undermines floodplain
management and flood control efforts in downstream communities, reduces
groundwater recharge, and threatens public health and safety.
B.
A comprehensive program of stormwater management, including reasonable
regulation of development and activities causing accelerated erosion
and loss of natural infiltration, is fundamental to public health,
safety, and welfare and the protection of the people of the municipality
and all of the people of the commonwealth, their resources, and the
environment.
C.
Stormwater can be an important resource by providing groundwater
recharge for water supplies and base flow of streams, which also protects
and maintains surface water quality.
D.
Public education on the control of pollution from stormwater is an
essential component in successfully addressing stormwater.
E.
Federal and state regulations require certain municipalities to implement
a program for stormwater controls. These municipalities are required
to obtain a permit for stormwater discharges from their separate storm
sewer systems under the National Pollutant Discharge Elimination System
(NPDES).
F.
Nonstormwater discharges to municipal separate storm sewer systems
can contribute to pollution of waters of the commonwealth.
The purpose of this chapter is to promote the public health, safety, and welfare within Upper Hanover Township by minimizing the damages and maximizing the benefits described in § 415-2 of this chapter by provisions designed to:
A.
Manage stormwater runoff impacts at their source by regulating activities
which cause stormwater problems.
B.
Utilize and preserve the desirable existing natural drainage systems.
C.
Encourage infiltration of stormwater, where appropriate, to maintain
groundwater recharge, to prevent degradation of surface and groundwater
quality, and to otherwise protect water resources.
D.
Maintain the existing flows and quality of streams and watercourses
in the municipality and the Commonwealth.
E.
Preserve and restore the flood-carrying capacity of streams.
F.
Provide for proper maintenance of all permanent stormwater management
BMPs that are implemented in the municipality.
G.
Provide review procedures and performance standards for stormwater
planning, design, and management.
H.
Manage stormwater impacts close to the runoff source which requires
a minimum of structures and relies on natural processes.
I.
Meet legal water quality requirements under state law, including
regulations at 25 Pa. Code § 93.4(a) to protect and maintain
"existing uses" and maintain the level of water quality to support
those uses in all streams, and to protect and maintain water quality
in "special protection" streams.
J.
Prevent scour and erosion of streambanks and streambeds.
K.
Provide standards to meet the NPDES permit requirements.
Upper Hanover Township is empowered to regulate these activities
by the authority of the Act of October 4, 1978, P.L. 864 (Act 167).
32 P.S. § 680.1 et seq., as amended, the Storm Water Management
Act, Act 247, the Pennsylvania Municipalities Planning Code of July
31, 1968, P.L. 805; 53 P.S. § 10101, as reenacted and amended.
This chapter shall only apply to all areas of the municipality.
The following activities are defined as regulated activities and shall
be governed by this chapter:
A.
Land development.
B.
Subdivision.
C.
Construction of new or additional impervious surfaces (driveways,
parking lots, etc.).
D.
Construction of new buildings or additions to existing buildings.
E.
Diversion or piping of any natural or man-made stream or channel.
F.
Installation of stormwater systems or appurtenances thereto.
G.
Regulated earth-disturbance activities.
H.
Any earth-disturbance activities or any activities that involve the
alteration or development of land in a manner that may affect stormwater
runoff onto adjacent property.
A.
Impervious cover. Any proposed regulated activity (except those defined in § 415-5E through H) that would create additional impervious cover is exempt from the drainage plan preparation provisions of this chapter only as provided in Table 1. If a site has previously received an exemption and is proposing additional development such that the total impervious cover on the site exceeds the amounts in Table 1, the total impervious cover on the site, proposed since the original ordinance date, must meet the provisions of this chapter.
|
TABLE 1
Impervious Area Exemption Criteria
| |||
|---|---|---|---|
|
Total Parcel Size
(gross acres)
|
Impervious Area
(square feet)
|
Minimum Distance*
(feet)
| |
|
0 to < 0.25 ac
|
1,000
|
10
| |
|
0.25 to < 0.5 ac
|
1,500
|
15
| |
|
0.5 to < 1 ac
|
2,500
|
20
| |
|
1 to < 2 ac
|
5,000
|
25
| |
|
2 to < 3 ac
|
7,500
|
50
| |
|
> 3 ac
|
10,000
|
50
| |
|
*
|
Note: The minimum distance between the proposed impervious area
and the down gradient property line.
|
(1)
The date of the municipal adoption of this chapter shall be the starting
point from which to consider tracts as "parent tracts" in which future
subdivisions and respective impervious area computations shall be
cumulatively considered.
(2)
For development taking place in stages, the entire development plan
must be used in determining conformance with these criteria.
(3)
Additional impervious cover shall include, but not be limited to,
additional indoor living spaces, decks, patios, garages, driveways,
storage sheds and similar structures, and roof, parking, or driveway
areas, and any new streets and sidewalks constructed as part of or
for the proposed regulated activity.
(4)
Any additional areas proposed initially to be gravel, crushed stone,
porous pavement, etc., shall be assumed to be impervious for the purposes
of comparison to the exemption criteria. Any existing gravel, crushed
stone, or hard-packed soil areas on a site shall be considered as
pervious cover for the purpose of exemption evaluation.
B.
Prior drainage plan approval. Any regulated activity for which a drainage plan was previously prepared as part of a subdivision or land development proposal that received preliminary plan approval from the municipality prior to the effective date of this chapter is exempt from the drainage plan preparation provisions of this chapter, except as cited in § 415-6D, provided that the approved drainage plan included design of stormwater facilities to control runoff from the site currently proposed for regulated activities consistent with ordinance provisions in effect at the time of approval, and the approval has not lapsed under the Municipalities Planning Code.
(1)
If significant revisions are made to the drainage plan after both
the preliminary plan approval and the effective date of this chapter,
preparation of a new drainage plan, subject to the provisions of this
chapter, shall be required.
(2)
Significant revisions would include a change in control methods or
techniques, relocation or redesign of control measures, or changes
necessary because soil or other conditions are not as stated on the
original drainage plan.
C.
Activities associated with § 415-5H shall be exempt from the drainage plan preparation requirements of this chapter unless the municipality determines that the activity could create a new or relocated concentrated drainage discharge onto adjacent property. Agricultural plowing and tilling as may be covered by § 415-5H are exempt from the drainage plan preparation requirements of this chapter.
D.
These exemptions shall not relieve the applicant from implementing
such measures as are necessary to protect health, safety, property,
and state water quality requirements. These measures include adequate
and safe conveyance of stormwater on the site and as it leaves the
site. These exemptions do not relieve the applicant from the responsibility
to secure permits or approvals for activities regulated by any other
applicable code, rule, act, or ordinance.
Approvals issued pursuant to this chapter do not relieve the
applicant of the responsibility to secure required permits or approvals
for activities regulated by any other applicable code, rule, act,
or ordinance.
Notwithstanding any provisions of this chapter, including exemption
and waiver provisions, any landowner and any person engaged in the
alteration or development of land which may affect stormwater runoff
characteristics shall implement such measures as are reasonably necessary
to prevent injury to health, safety, or other property. Such measures
shall include such actions as are required to manage the rate, volume,
direction, and quality of resulting stormwater runoff in a manner
which otherwise adequately protects health and property from possible
injury.
